Operating mechanism for blow-off cocks



July 1, 1930. F. WILSONEI' AL 1,769,006

OPERATING MECHANISM FOR BLOW-OFF COCKS I Filed June 24, 1927 Patented July 1,1930

UNITED STATES LYNDON r. wI'LsoN. or OHICAGO,"AND JOHN '1. nee mrn; or BLooMme'ron, ILLINOIS PATENT oFFIc-E- OPERATING MECHANISM" FOR BLOW-OFF COCKS Application filed June 24,

This invention relates to blow-off cocks'and operating mechanism therefor for steam boilers in general. and locomotive boilers in particular.

The exceedingly high steam pressures which are coming to be used in locomotive boilers are making it much more diflicult than heretofore to open the blow-0H cocks by hand.

It is accordingly the primary object of this invention to providea blow-off cock and operating mechanism therefor which may be operated with very little effort.

It is also an object of this invention to provide a pressure operated blow-off cock.

It is further an object ofthis invention to provide a blow-off cock and operating mechanism therefor adapted to be used on a locomotive] and operated by the pressure in the main air reservoir. I V It is also an objectof this invention to provide a pressure operated blow-01f cock which is not in danger of opening or being left open by failure of. the pressure operating mechanism. I

Other and further objects of this invention will be apparent as the same becomes better understood from an examination of the specification and claims in connection with the accompanying drawings wherein,

Fig. 1 representsa fragmentary section of a locomotive and cab showing a valve embodying this invention secured to the boiler of the locomotive. and connected for operation from the cab.

Fig. 2 is an enlarged section of the valve proper withparts inelevation and parts omitted.

Fig. 3 is a fragmentaryend view of the valve as viewed from the right of Fig. 2.

Referring to the drawings'more'particularly, reference numeral 6 indicates generally a locomotive, the boiler of which is provided with an outer shell 7 to which'is attached a blow-ofi cock represented generally by the reference numeral 8. The housing of the blow-off cock 8 is provided at its inner end with a triangular flange 9 by which the cock is attached to the shell 7 of the boiler through a plurality of studs or bolts 11; The housing 59 of the cock is provided with three ears, 12 upon 1927. Serial No. 201,094.

either one ofwhich an operating lever 13 may be fulcrumed. In the illustration shown'the lever 13 is fulcrumed on the upper ear 12 but may, if desired, be fulcrumed on either V flange 9, preferably through the shell 7 of the boiler. Between its ends the housing of the a cock isprovided with a downwardly directed discharge spout 18 which may be lengthened to any desiredextent. A protective cage 19 around the tubular. extension 16 snugly. fitting the same and the hole in the boiler shell is clamped between said shell andthe flange 9.

A collar fitted onthe stem 14 between the lower end of the lever 13 and housing of the cock is provided with a gasket 22 wh ereby when the stem is moved to the left to open the valve the gasket will seal the opening in said housing provided for said, stem; v

The parts thus far described are of well known construction and in operation the valve 15 is normallyseated as shown in Fig. 1, but when blowing off of the boiler is desired it is: necessary to force the. valve in wardly awayfrom its seat against the boiler pressure so as to permit the sludge and other undesirable foreign matter to be discharged from the boiler. i

It is frequently very diflicult to actuate a valve by manually operating the lever. 13 to the right. as shown in Fig. 1 because. of the high pressure in the boiler and a possible accumulation of sludge around thevalve. It

is also an advantage to be. able. to operate the valve with. a maximum of convenience from the cab as frequent blowing down of the boiler even when the locomotive is under way promotes greater efficiency in maintenance and operation. To this end I mount a cylinder-23 alongside of the blow-off cock provided'with an open outer end and an upper flange 24 and a lower flange 25 on opposaid circular portion is slidably mounted within the said cylinder and is provided with a connecting rod 31 pivotally attached at its outer end to the lever 13 whereby movement of the piston to the right will open the valve 15 to permit blowing down of the boiler.

The movement of the piston 27 may be controlled conveniently from the ,cab by means of a valve 32 of the character disclosed in patent No. 1,037,789 of September 3, 1912.

The valve 32 includes a body 33, two valve members 34 and 35, and a handle 36 adapted upon being tilted from the normal position shown to actuate first said valve 34 and then said member 35. The intake side of both of the valve'members 34 and 35 is in communication with the main air reservoir of the locomotive by means of a pipe 37. The member 34 is upon actuation adapted to discharge air from the air line to the cylinder 23 011 the outer side of the piston 27 by means of a pipe connection 38. The member 35 upon actuation is adapted to discharge air from the air line by means of a pipe connection 39 to the cylinder 23 on the inner side of the piston'27. A circular flange 41 integral with the outer end of the cylinder 23 extends inwardly to the periphery of the cylindrical portion 29 of the piston so as to retain the air admitted to the cylinder by the valve 34. The effective area to the right of the circular portion 28 of the piston is considerably less than the area to the left of said portion whereby'the air admitted by the valve 34 will be compressed by the air subsequently admitted bythe valve 35 and the piston will be moved outwardly to the right by the latter air, the air admitted'by the valve 34 acting to cushion the outward stroke of said piston. The body 33 is provided with an exhaust opening 42 which is normally open but is closed when the valve member 33 is opened such that when the handle 36 is released. and automatically returned to the po sition shown in Fig. 1 the air on'the inner side of thepiston will be exhausted through the opening 42 before the valve 34 is closed, thereby allowing the air pressure to the right of the piston together with the'pressure of thesteam in the boiler to force the blow-off cock valve 15 closed. The pressure in the boiler will normally keep the valve 15 closed and will eventually close the same when once opened if the pressure 'mechanism should fail thus promoting safety.

By the use of the foregoing apparatus the locomotive boiler may be blown down very conveniently when the locomotive is under way, thus promoting greater efliciency in maintenance and operation.

We are aware that many changes may be made throughout a wide range without departing from the principles of this invention and we therefore do not wish to be limited to the details shown and described.

We claim:

1. The combination with a boiler shell, of a. blow-01f cock connected to said shell and provided Witha valve, a pressure cylinder in proximity to said cock, a differential piston having two faces of substantially unequal area operable in said cylinder and operatively connected to the stem of said valve for actuating the same, means for admittinga fluid under pressure to one side of said piston for actuating the same, and means for admitting a further quantity of the same fluid under the same pressure to the other side of said piston for cushloning the movement of saidpiston in the direction of its lesser face.

2. The combination with a boiler shell, of a blow-off cock connected to said shell and provided with a valve, a pressure cylinder in proximity to said cock and a piston operable in. said cylinder and operatively connected to the stem of said valve for actuating the sa1ne,'and means for admitting a fluid under pressure simultaneously to both sides of said piston, the effective area on one side of the piston being considerably less than that on the other'side whereby'the piston is caused to move toward the side of lesser area displacing the fluid on that side with cushioning effect on the piston movement.

3. The combination with a boiler shell, of a blow-oil" cock connected to said shell and provided with a valve, a pressure cylinder in proximity to said cock, a differential piston having two faces of substantially unequal area operable in said cylinder and operatively connected to the stem of said valve for actuating the same, means for admitting a fluid under pressure to the smaller side of said piston for retarding the opening move ment thereof to cushion the same, and means for admitting a fluid under pressure to the larger side of said piston while said smaller side is under said pressure for actuating the piston against the pressure of the first fluid to open said valve.

4. The combination with a boiler shell, of a blow-off cock connected to said shell and provided with a valve, a pressure cylinder in proximity to said cook, a piston operable in said cylinder and operatively connected to the stem of said valve for actuating the same, the effective area on one side of the piston being less than that on the other side, means for admitting a fluid under pressure to said sure on both faces, said means being adapted to close said valve by releasing said prescylinder on the side of the piston having the larger effective area to cause the actuation of the piston to open the valve, and means for admitting a fluid under pressure to the side of said piston having a lesser effective area to cushion the movement of the piston.

5. The combination With a boiler shell, of a blow-off cock connected to said shell and providedwvith a valve, a pressure cylinder in proximity to said cock, a differential piston having substantially unequal facesoperable in said cylinder and operatively connected to the stem of said valve for actuating the same, means for admitting a fluid under pressure into the cylinder at the larger side of said piston for actuating the same, and means for preliminarily admitting a fluid under pressure in the cylinder at the smaller side of said piston for cushioning the movement of the piston. 1 r

6. The combination with a boiler shell, of a blow-off cock connected to said'shell and provided With a valve, a pressure cylinder in proximity to said cock, a piston operable in said cylinder and operatively connected to said valve for actuating the same, the effective area on one side of said piston being less than that on the other side, means for initially admitting a fluid underpressure to said cylinder at the side of said piston having the lesser effective area for cushioning the movement of thepiston, and means for subsequently admitting a fluid under pressure to said cylinder having the large effective area for actuating the piston.

7 The combination With a boiler shell, of a blow-off cock connected to said shell and provided With a valve, apressure cylinder in proximity to said cock and a piston operable in said cylinder and operatively connected to the stem of said valve for actuating the same, said piston having faces of substantially unequal area, and means for communicating a fluid pressure to both sides of said piston simultaneously and for permitting movement of the piston in the direction of its lesser face While maintaining said pressure on both faces.

8. The combination With a boiler shell, of a blow-off cock connected to said shell and provided With a valve, a pressure cylinder in proximity to said cock and a piston operable in said cylinder and operatively connected to the stem of said valverfor actuating the same, said piston having faces of substantially unequal area, means for communicating a fluid pressure to both sides of said piston simultaneously and for permitting movement of the piston in the direction of its lesser face While maintaining said pressure on the larger side of the piston While retaining pressure on the smaller side of the of said piston simultaneously and for permitting movement of the piston in the direction if its lesser face While maintaining said pressure on both faces.

10. In combination With a valve casing provided with a valve, a pressure cylinder in proximity to said valve casing and a piston operable in said cylinder and operatively connected to the stem of said valve for actuating the same, said piston having faces of substantially unequal area, means for communicating a fluid pressure to bothsides of said piston simultaneously and for permitting movement of the piston in the direction of its lesser face While maintaining said pres sure on both faces, said means being adapted to closesaid valve by releasing said pressure on the largerside of the piston While retaining pressure on the smaller side-of the piston, the latter pressure thereupon closing the valve.

In Witness of the foregoing We affix our signatures LYNDON F. WILSON. J NO. T. MCGRATH. 

